Structure and magnetic properties of sputtered (Nd,Dy)(Fe,Co,Nb,B)[sub 5.5]/M (M=FeCo,Co) multilayer magnets.

The magnetic properties of nanocomposite multilayer magnets of the (Nd,Dy) (Fe,Co,Nb,B)[sub 5.5]/M (M = Co,FeCo) on Ti-buffered Si substrates have been investigated. X-ray diffraction results reveal that the Nd[sub 2]Fe[sub 14]B-type phase in almost all the films is randomly oriented. Different thickness χ (nm) for Co layers and y (nm) for FeCo layers were adopted in the multilayers. It is found that high remanence is achieved in the nanocomposite multilayer films consisting of the Nd[sub 2]Fe[sub 14]B-type phase and soft magnetic phase for Co with 6 ≤ χ ≥ 4 and for FeCo with 10 ≥ y ≥ 6. The enhancement of the remanence in the nanocomposite multilayer films is attributed to the exchange coupling between the magnetically soft and hard phases. Increasing the soft magnetic components results in a continuously decreasing coercivity. [ABSTRACT FROM AUTHOR]